<!-- 
https://css-loaders.com/pulsing/ 
-->

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      /* HTML: <div class="loader"></div> */
      .loader {
        width: 50px;
        aspect-ratio: 1;
        color: #dc1818;
        background: radial-gradient(
              circle at 60% 65%,
              currentColor 62%,
              #0000 65%
            )
            top left,
          radial-gradient(circle at 40% 65%, currentColor 62%, #0000 65%) top
            right,
          linear-gradient(to bottom left, currentColor 42%, #0000 43%) bottom
            left,
          linear-gradient(to bottom right, currentColor 42%, #0000 43%) bottom
            right;
        background-size: 50% 50%;
        background-repeat: no-repeat;
        position: relative;
      }
      .loader:after {
        content: "";
        position: absolute;
        inset: 0;
        background: inherit;
        /* background:radial-gradient(
              circle at 50%,
              currentColor 60%,
              #0000 60%
            ); */
        opacity: 0.4;
        animation: loveFrames 1s infinite;
      }
      @keyframes loveFrames {
        /* to {
          transform: scale(2);
          opacity: 0;
        } */
        0%{
          transform: scale(1);
          opacity: 0.4;
        }
        50%{
          transform: scale(1.5);
        }
        100%{
          transform: scale(2);
          opacity: 0;
        }
      }
    </style>
  </head>
  <body>
    <div class="loader"></div>
  </body>
</html>
